Personal ballistic body armor, particularly vests, helmets, and other articles, are formed generally of materials which serve to prevent penetration of a bullet or other projectile, and any other object that is forcefully applied to the armor, such as a knife. These articles are primarily used for the armed forces, but also have police and civilian applications. There is a growing demand to improve the wearability and the overall effectiveness of armor systems used by soldiers and police offices in combative environments. Overall thickness and weight of armor systems can effect wearability, but reducing these parameters in currently known systems can compromise the armor's effectiveness against penetration.
Fabrics known for ballistic applications include those having at least two layers having unidirectional fibers such that the fibers in the second layer are skew to fibers in the first layer are known. See, for example, U.S. Patent Application Nos. 2002/0164911, 2003/0228815, and 2005/0081571.
Similar constructions have been impregnated with a binding material. See, U.S. Patent Application No. 2004/0045428 and U.S. Pat. No. 6,238,768. U.S. Pat. No. 5,160,776 discloses a composite which has at least one layer that is network of certain high strength filaments in a matrix material. U.S. Pat. No. 4,183,993 discloses the use of laminates in a unidirectional reinforcing fabric that includes a weft knit yarn fabric formed of a multiplicity of weft knit stitches and a multiplicity of parallel longitudinally extending warp inserts held in the weft knit fabric.
U.S. Pat. No. 5,935,678 discloses a ballistic laminate structure in sheet form that includes first and second arrays of unidirectionally-oriented fiber bundles. The second array of fiber bundles is cross-plied at an angle to the first array of fiber bundles. In this construction, a polymeric film resides between the first and second cross-plied arrays of fiber bundles so as to adhere the first and second arrays of fiber bundles together without substantial penetration of the film into the fiber bundles. U.S. Pat. No. 5,677,029 discloses a ballistic article having at least one fibrous layer and at least one polymeric layer that is in contact with and bound to all or portion of the fibrous layer.
Certain fabrics containing both woven and nonwoven layers are also known. See, U.S. Patent Application No. 2004/0132368.
There is a need for ballistic fabrics and articles with improved performance.